TIMBER BREAKAWAY GUARDRAIL POSTS

Tests are described which were designed to determine whether wood posts could adequately serve in breakaway (weak post) systems. There are 2 basic types of weak-post systems in current use. One utilizes a so- called strong beam, usually rectangular, welded steel tubing; the other uses a flexible railing, generally a standard steel W-rail (flex-beam) but ocassionally a steel-cable system. Data indicate that so long as the 1/4- inch bolt and the pipe insert are used, weak-wood posts could vary from 4- by 6-inch rough sawn, with no significant differences in system performance. These 2 are standard timber sizes. An alternate size is the 5 1/2 plus/minus 1/2 inch diameter, round wood post. Any of these three sizes will break under impact in the weak post system, where post spacing is 12.5 feet. Comments are also made regarding rail to post connection and railing height.

  • Corporate Authors:

    American Wood Preservers Institute

    1651 Old Meadow Road
    McLean, VA  United States  22101
  • Publication Date: 1970-12

Media Info

  • Features: Appendices; Figures; Photos; References;
  • Pagination: 6 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00153017
  • Record Type: Publication
  • Report/Paper Numbers: Report No. H3
  • Files: TRIS
  • Created Date: Jul 19 1977 12:00AM